Pd-catalyzed ortho-C-H acylation/cross coupling of aryl ketone O-methyl oximes with aldehydes using tert-butyl hydroperoxide as oxidant

A Pd-catalyzed protocol for direct C-H bond acylation by cross coupling of aryl ketone oximes and aldehydes using tert-butyl hydroperoxide (TBHP) as oxidant was developed. With oximes as a directing group for the C-H activation, the coupling with aldehydes was achieved with remarkable regioselectivity. The acylation reactions exhibit excellent functional group tolerance, and both aliphatic and heteroaromatic aldehydes can be effectively coupled to the oximes.